0

So I've attached the images of this weird piece of metal "on" the smallest cog of the cassette. Can anyone advise me on what is happening here?

It does not interfere with the riding as far as I can tell, but also doesn't really look right :)

enter image description here enter image description here enter image description here enter image description here enter image description here enter image description here

Dima
  • 173
  • 1
  • 1
  • 6

2 Answers2

2

The part is the aluminum washer/shim that's used between the cassette lockring and smallest cog. For some reason it isn't centered, thus it has been damaged. Most likely it's damaged so much that it needs to be thrown away. You get new one by purchasing a new lockring, and the new washer/shim should be centered.

The same (or possibly similar but not exactly the same) washer/shim is used with centerlock disc brake rotors, where it prevents the rotor from having free play.

I suspect that when used with cassettes, it makes the cassette fit more securely, thus the shifting could be a bit more accurate. However, I suspect it isn't doing as important job with cassettes as it it with centerlock disc brake rotors, because disc brake rotors sometimes see reverse forces when you hold the bicycle still using the brakes on an upwards incline. Then it's preferable that the disc brake rotor stays still when encountering forces in alternating directions.

If you want to cheap out, you could of course remove the lockring, throw away the washer/shim and reinstall using only the lockring. I suspect it might even work.

juhist
  • 18,668
  • 3
  • 27
  • 49
  • With cassettes a tight fit is important to avoid the sprockets biting into aluminium freehub bodies. – Michael Oct 03 '21 at 11:48
  • 2
    I disagree; aluminum freehub bodies are doomed by design. Tight fit doesn't prevent the problems. – juhist Oct 03 '21 at 13:23
  • 1
    The alloy washer under the lock ring is included on higher end cassettes whose lock ring is alloy. The cogs are steel and the smallest cog has ridges on its inner circumference that mesh with the ridges of the alloy lock ring as a defense against loosening. That washer is present to help spare the ridges of the softer alloy lock ring of a part that may be removed and refitted multiple times over the life of the cassette. Cheaper cassettes use steel lock rings and note there is no thin washer present on those. – Jeff Oct 03 '21 at 14:45
  • 2
    @Jeff Counterexample: my SLX M7000 cassette has a steel lock ring and a washer. At least it had a washer; it disintegrated after a couple of installation cycles. – MaplePanda Oct 03 '21 at 16:34
  • 2
    @MaplePanda That's true. Specs say it's a "plated steel" lock ring, where other, lower tier lock rings say, Ni plated, phosphate coated, or simply, steel. They do get mangled pretty good--my SLX washer is more distorted than my XT's with about equal install/removal cycles. – Jeff Oct 03 '21 at 18:21
  • 1
    It's not true that aluminum freehub bodies are doomed by design. Consider Campagnolo bodies; their splines are much deeper. I have run Veloce cassettes (i.e. none of the cogs are pinned) and never gouged a Campy FH body. It's the fact that the Hyperglide splines are shallow that dooms the design to gouging if it's done in aluminum (and it seems like Shimano may have thought, wrongly, that everyone would do it in steel or ti). – Weiwen Ng Oct 05 '21 at 17:44
-1

Do you mean the lockring? The circle with all the words on it is essentially a big nut, that threads on and holds the cassette on the splines.

Without a locknut, the cassette could move left and right on the freehub body, and it could hit then bind on the inside of the dropouts.

If the cassette was free to move, then the slack will increase wear on your freehub's mating surfaces.

Generally, a new cassette is sold with a new lockring. I've sometimes kept the old one when installing a new cassette, sometimes riders prefer black or silver. They are sized too, yours is 11 speed, and its best to use the right one.

But you do need a cassette lockring.

If the look annoys you, then you could paint it, or colour it in with a permanent marker pen.

Criggie
  • 124,066
  • 14
  • 180
  • 423
  • 2
    I think OP is referring to the thin spacer between the lockring and the smallest sprocket. Looks like the spacer is not quite centered which caused its edge to get hit&bent by the chain. I think the biggest question is if the spacer is actually required, why it’s not centered and if it could be placed between biggest sprocket and freehub body. – Michael Oct 03 '21 at 11:22
  • 1
    @Michael could be... I thought that little flake was a piece of grass, but yes it could be a thin spacer of some sort. Would be odd to have it between cassette and lockring though, that's where the indents/serrations are. – Criggie Oct 03 '21 at 11:25
  • 2
    I think I’ve had such a spacer between lockring and cassette on one of my bikes when I got it from the store. Not sure what it is for. I’m pretty sure the spacer you need to run 10 speed (or 11 speed MTB) cassette on 11 speed road freehub bodies is thicker. – Michael Oct 03 '21 at 11:29
  • 2
    @michael yes - that spacer is to go on the freehub first, before the cassette. Otherwise the lockring teeth don't fasten down onto the matching part of the cassette - there would be two smooth faces of the spacer between the serrations. – Criggie Oct 03 '21 at 12:34
  • 1
    Some lockrings do have those spacers made from wafer-thin Al. They may be left away because with or without, the cassette sits tight enough on the rotor without sideways movement. – Carel Oct 04 '21 at 08:21